Lacquering apparatus and method

ABSTRACT

A lacquering line and a method of lacquering industrially manufactured products in standard and/or special colours, having one or more guide devices ( 1 ) for the industrially manufactured products, having one or more lacquering cabins and having spraying elements ( 2 ) disposed along the guide devices ( 1 ) inside the lacquering cabins, wherein at least one lacquering cabin comprises one or more lacquering units, having one or more exchangeable small containers ( 6, 6   a ), in which the lacquer quantity required for lacquering a predetermined number of individual products is packed ready to apply, as well as having a rinsing device ( 9 ), wherein the small containers ( 6, 6   a ) and the rinsing device ( 9 ) are connectable in each case by a lacquer conveying device ( 7 ) and one or more stub lines ( 8 ) directly or via a colour changer ( 11 ) to the spraying elements.

FIELD OF THE INVENTION

The invention relates to a lacquering apparatus or lacquering line aswell as to a lacquering method, which may be effected with saidapparatus, for in particular products manufactured on an industrialscale or parts thereof, such as, for example, motor vehicle bodies orparts thereof.

In the following, the invention is described using the example of thelacquering of motor vehicle bodies although it is naturally alsoapplicable to the lacquering of industrial products such asrefrigerators and other appliances.

BACKGROUND OF THE INVENTION

Series lacquering of automobiles occurs in fully automated automobilelacquering lines, with application of the colour-determining lacquerlayer (as a final outer lacquer layer or as a base lacquer layer of atwo-coat lacquering comprising a base lacquer layer and an outertransparent lacquer layer) being effected in a limited number ofstandard colours, e.g. between 5 and 15, with frequent colour changing.The colour changing arises as a result of the production schedule andgenerally does not occur after the lacquering of just one body, thebodies instead usually being combined into groups of identical colour.The standard colours are lacquers, which are processed in bulk and aretherefore in practice fed in each case from a lacquer storage containerhaving a filling volume of e.g. 200 to 1500 litres through a separatering line connected thereto to the lacquer spraying elements. Automaticcolour changing merely involves a switchover by a colour changer fromone ring line to another ring line containing lacquer of anotherstandard colour and the lacquer spraying elements are automaticallyrinsed between the end of application of the one standard colour and thestart of application of the next standard colour. In the case of supplyby means of ring line systems, it is customary for the lacquers in thering lines and storage containers to be circulated in order to ensure auniform colouring and avoid separation of the lacquer. In said case, thelacquer in the agitating and pumping mechanisms is subject to increasedshear, which may lead to a loading of the lacquer. For such aneventuality, it is usually necessary to take suitable counter-measures,e.g. the addition of additives or a particular choice of binding agents.

At the special request of customers, automobile manufacturers alsolacquer individual vehicles or a low number of vehicles in specialnon-standard colours. The number of special colours far exceeds thenumber of standard colours and the special colours are processed only insmall quantities compared to the standard colours. The special coloursmay be recurring colours but are predominantly one-off colours. Sincethe individual lacquering of motor vehicle bodies requires only around 4to 10 litres of the colour-determining lacquer, it is thereforeuneconomic and labour-intensive to use the same lacquering procedure forspecial colours as for standard colours. The use, for speciallacquering, of the storage containers and ring lines customary forstandard lacquering would entail a considerable surplus of lacquer,which would ultimately have to be thrown away. Furthermore, the rinsingof storage container and ring line would lead to additional expenditureof effort, additional use of solvent and additional disposal problems.

In practice, therefore, motor vehicle bodies which are to be lacqueredin special colours are transferred out of the normal lacquering line forseries lacquering and moved to a separate lacquering cabin or lacqueringline. As a rule, bodies which have been precoated, e.g. provided with alayer of primer and filler, are transferred out of the lacquering lineand lacquered e.g. with the base lacquer in a special colour. Then atransparent lacquer may be applied likewise in a separate manner or thebody, having been lacquered in the special colour in a separate device,is then transferred back into the lacquering line, where it is providedwith the outer transparent lacquer layer and conveyed to the furtherconventional lacquering and stoving devices. This requires additionaltechnical appliances outside of the conventional lacquering line as wellas elaborate operations for transferring the body to be separatelylacquered out of and back into the conventional lacquering line.

In “Journal für Oberflächentechnik” JOT, 9, 1996, page 28, Graudescribes how it may be possible in future to dispense with theconventional lacquer supply using lacquering robots. The central featureof the new system is a magazine having a flexible number of exchangeablecontainers. Integrated into the magazine are devices for filling andrinsing an exchangeable container. The system automaticallydistinguishes between the colours of a high or low consumptionprobability, i.e. it distinguishes between standard and special colours.At the point of use, refilling of the colour containers of the highconsumption probability is effected, while the colour containers of alow consumption probability first have to be rinsed. Depending onrequirements, filling may be effected via a ring line or manually.Reference is made to the extreme suitability of the system for applyingspecial colours on account of the possible savings on lacquer materialcompared with the conventional procedure of the filling of ring lines.The procedure described here however also inevitably involves handlingof the lacquers by the operator, e.g. liquid lacquer has to be handledparticularly during filling and emptying operations at the exchangeablecontainers. Furthermore, it is necessary to rinse at least theexchangeable containers for special colours. All of this constitutes notonly an undesirable expenditure of effort for the operator but alsoentails risks of contamination, particularly in connection with rinsingand cleaning operations at the exchangeable containers. The operator isnamely compelled to guarantee an adequate cleanness of the containersprior to refilling.

From DE 28 19 302 B2 a lacquering line is known, having a guide devicefor vehicle bodies and having spray elements, which are disposed alongthe guide device inside a spraying cabin and are connected by feed linesvia one or more ring lines to one or more lacquer storage containers.Also described is a cleaning process for contaminated lines and sprayingelements. One or more units for the individual lacquering of bodies orbody parts are integrated into the apparatus. The controllable lacquerpressure regulators perform the function of colour changers connected tothe spray elements.

From JP-2-280866 A in: Patent Abstracts of Japan, C-802, Vol. 15, No. 48of 05.02.1991, a plurality of small paint containers combined into aunit are known, which are connectable by a colour changer to a sprayingelement.

From DE 40 13 941 A1 a small container of a vehicle body lacqueringinstallation is known, the total filling volume of which is sufficientfor lacquering one body or one part thereof.

SUMMARY OF THE INVENTION

The object of the invention is to provide an apparatus and a method,which may be effected with said apparatus, for lacquering, in particularfor the individual lacquering or the series lacquering of productsmanufactured industrially in high numbers, e.g. preferably for theseries lacquering of motor vehicles or parts thereof with lacquers. Inso doing, products are to be capable of manufacture in differentcolours, in accordance with a colour range.

Examples are the lacquering of base layers and outer layers in standardand/or special colours. An efficient design of the apparatus as well asan efficient process control are to be made possible. Filling andemptying operations involving liquid lacquer, as well as rinsing andcleaning steps within the apparatus are to be extensively avoided.

It has been shown that said object may be achieved by the apparatusforming the subject-matter of the invention in the form of a lacqueringline for lacquering industrially manufactured products in standardand/or special colours, having one or more guide devices for theindustrially manufactured products, having one or more lacquering cabinsand having spraying elements disposed along the guide devices inside thelacquering cabins, which is characterized in that at least onelacquering cabin comprises one or more lacquering units, having one ormore exchangeable small containers, in which the lacquer quantityrequired for lacquering a predetermined number of individual products ispacked ready for application, as well as having a rinsing device,wherein the small containers and the rinsing device are connectable ineach case by a lacquer conveying device and one or more stub linesdirectly or via a colour changer to the spraying elements.

The invention also relates to the lacquering method which may beeffected with the apparatus.

The apparatus according to the invention is suitable for a method oflacquering industrially manufactured products in standard and/or specialcolours using the apparatus. The apparatus as well as the method aresuitable for parallel operation of a lacquering line for the serieslacquering of motor vehicle bodies in standard colours and specialcolours. The lacquers in a standard and/or special colour, which arepacked ready for application in a predetermined quantity required forlacquering, are fed from small containers located in the vicinity of thespraying elements. This may occur, for example, in a conventionallacquering line for motor vehicle bodies and a transfer of bodies to belacquered in a special colour out of the conventional lacquering linemay be avoided. Furthermore, there is in particular no need for lacquerstorage containers and ring lines connected thereto to be filled withlacquers for special colours and subjected, after the individuallacquering, to elaborate emptying and rinsing operations with theassociated material losses.

The spraying elements as such are not subject to any restrictions, itbeing possible to use conventional spraying elements for the applicationof liquid coating agents. Examples are manually operated orautomatically controlled spraying elements, e.g. spray guns, high-speedrotary bells, lacquering robots and automatic lacquering machines. Thespraying elements may be operated pneumatically or without airassistance, optionally with electrostatic assistance.

Nor is the nature of the industrially manufactured products to belacquered subject to any fundamental restriction, the industriallymanufactured products preferably being motor vehicle bodies or partsthereof. The term “products” used here means industrially manufacturedproducts, preferably motor vehicle bodies and parts thereof. Thus, theinvention, in terms of the lacquering of industrially manufacturedproducts, preferably relates to a lacquering line for the serieslacquering of motor vehicle bodies in standard and/or special colours aswell as to a method of lacquering within the lacquering line. In saidcase, the lacquers in a standard and/or special colour are, within thelacquering line which comprises one or more lacquering cabins forapplying the lacquers in a standard and/or special colour, packed readyfor application in a predetermined quantity required for lacquering andfed from small containers located in the vicinity of the sprayingelements.

The lacquering units used according to the invention and comprisingsmall containers may be provided in separate lacquering cabinsintegrated into the lacquering line. They may however alternatively beintegrated into conventional lacquering cabins provided with one or morering lines.

Thus, the invention according to a first embodiment relates to alacquering line for lacquering industrially manufactured products instandard and/or special colours, having one or more guide devices forthe industrially manufactured products, having one or more lacqueringcabins and having spray elements disposed along the guide devices insidethe lacquering cabins, wherein at least one lacquering cabin A comprisesone or more lacquering units having one or more exchangeable smallcontainers, in which the lacquer quantity required for lacquering apredetermined number of individual products is packed ready forapplication, as well as a rinsing device, and wherein the smallcontainer or containers and the rinsing device are connectable in eachcase by a lacquer conveying device and one or more stub lines directlyor via a colour changer to the spraying elements, and optionally for thelacquering in standard colours is equipped with one or more furtherlacquering cabins B comprising spraying elements, which are disposedalong the guide devices inside said lacquering cabins and are connectedby feed lines via one or more ring lines to one or more lacquer storagecontainers and a rinsing device.

In the first embodiment of the invention, a distinction has to be madebetween lacquering cabins of type A, referred to as lacquering cabins orspraying cabins A, and lacquering abins of type B, referred to aslacquering cabins or spraying cabins B. In the case of the sprayingelements isposed inside the lacquering cabins A, the lacquer supply iseffected exclusively via a small container system, i.e. a lacqueringcabin A is a lacquering cabin, inside which spraying elements aredisposed, wherein the lacquering cabin comprises one or more lacqueringunits, wherein one unit comprises one or more exchangeable smallcontainers, in which the lacquer quantity required for lacquering apredetermined number of individual products is packed ready forapplication, as well as a rinsing device, and wherein the smallcontainer or containers and the rinsing device are connectable in eachcase by a lacquer conveying device and one or more stub lines directlyor via a colour changer to the spraying elements. In the case of thespraying elements disposed inside the lacquering cabins B, on the otherhand, the lacquer supply is effected exclusively via a ring line system,i.e. a lacquering cabin B is a lacquering cabin, which is supplied withlacquer in a conventional manner and inside which are disposed sprayingelements, which are connected by feed lines via one or more ring linesto one or more lacquer storage containers and a rinsing device.

For example, the lacquering line within the first embodiment of theinvention comprises a plurality of lacquering cabins for the applicationof lacquers in a standard and/or special colour, e.g. two lacqueringcabins, wherein in the respective lacquering cabins different coloursfrom the colour range are applied. Thus, for example, in the onelacquering cabin the standard colours may be applied and in the furtherlacquering cabin(s) the special colours may be applied. In said case,the lacquer supply in standard colours may be effected in the usualmanner, i.e. using the known, initially mentioned lacquer storagecontainers and ring lines, i.e. in lacquering cabins B. The lacquersupply in standard colours is however preferentially effected using thesmall container system, i.e. in lacquering cabins A. The lacquer supplyin special colours, on the other hand, is effected exclusively using thesmall container system, i.e. in lacquering cabins A. In said case, theproducts to be lacquered in special colours are fed to the lacqueringcabin A used for applying the special colours. For example, productswhich have been precoated, e.g. provided with a layer of primer andfiller, are lacquered with base lacquers of a special colour. Then atransparent lacquer may be applied or the products lacquered in specialcolours are re-inserted between products lacquered in standard coloursand then provided with the outer transparent lacquer layer and fed tothe further customary lacquering and stoving devices. By virtue of theinvention, there is no need for lacquer storage containers and ringlines connected thereto to be filled with lacquers for special coloursand subjected, after lacquering, to elaborate emptying and cleaningoperations with the associated material losses. In the preferred case ofthe supply of lacquers in standard colours being effected likewise usingthe small container system, the same advantages arise as for the specialcolours.

Thus, the first embodiment of the invention relates to a lacquering linefor the series lacquering of industrially manufactured products, havingone or more guide devices for the products and having spraying elementsdisposed along the guide devices inside two or more spraying cabins,wherein the spraying elements in the spraying cabin or cabins B, e.g.the spraying cabins operated with standard colours, may be connected byone or more ring lines to one or more lacquer storage containers and arinsing device. In the case of said lacquering line, in the furtherspraying cabin or cabins A, e.g. the spraying cabin(s) operated withspecial colours, the lacquer supply to the spray elements operatedtherein is not effected from lacquer storage containers via ring lines.Preferably, the lacquer supply in none of the spraying cabins iseffected from lacquer storage containers via ring lines, rather all ofthe spraying cabins are spraying cabins A, which comprise one or moreunits for lacquering products, wherein the respective unit comprises oneor more exchangeable small containers, the total filling volume of whichcorresponds to the lacquer quantity required for lacquering apredetermined number of individual products, as well as a rinsingdevice, wherein the small containers and the rinsing device areconnectable in each case by a lacquer conveying device and one or morestub lines directly or via a colour changer to the spraying elements.

In a preferred manner, the lacquering line within the first embodimentof the invention comprises only one lacquering cabin A, in whichstandard and/or special colours are applied. The supply of lacquer instandard and/or special colours is in said case effected exclusivelyusing the small container system. Operations for the inward and outwardtransfer of products to be lacquered may be avoided. Also eliminated arethe customary ring line systems and the drawbacks associated therewith.

A preferred subject-matter of the invention is therefore formed by alacquering line for the series lacquering of industrially manufacturedproducts, having a guide device for the products and having sprayingelements disposed along the guide device inside only one spraying cabinA, wherein the spraying elements are connected to one or more units forlacquering the products, wherein the respective unit comprises one ormore exchangeable small containers, the total filling volume of whichcorresponds to the lacquer quantity required for lacquering apredetermined number of individual products, as well as a rinsingdevice, wherein the small containers and the rinsing device areconnectable in each case by a lacquer conveying device and one or morestub lines directly or via a colour changer to the spraying elements.

In a second embodiment, the invention relates to a lacquering line forlacquering industrially manufactured products in standard colours andspecial colours, having a guide device for the industrially manufacturedproducts and having spraying elements, which are disposed along theguide device inside one or more spraying cabins C and are connected byfeed lines via one or more ring lines to one or more lacquer storagecontainers and a rinsing device, wherein the lacquering line hasintegrated therein one or more units for the individual lacquering ofproducts, wherein one unit comprises one or more exchangeable smallcontainers, the total filling volume of which corresponds to the lacquerquantity required for lacquering a predetermined number of individualproducts, as well as an additional rinsing device, wherein the smallcontainers and the additional rinsing device are connectable in eachcase by a lacquer conveying device and one or more stub lines directlyor via a colour changer to the spraying elements. In the case of thespraying elements disposed inside the lacquering cabin or cabins C, thesupply of lacquer in the special colours is effected via a smallcontainer system as described above for the lacquering cabins of type A,while the supply of lacquer in the standard colours is effected via aring line system as described above for the lacquering cabins of type B.

In said second embodiment of the apparatus according to the invention,the same spraying elements may be used both for lacquering in standardcolours and for lacquering in special colours. The spraying elements aregenerally located close to one another. They are disposed along theguide device for the products which are to be lacquered, e.g. vehiclebodies, i.e. laterally of, as well as above, the guide device andoptionally also under the guide device.

It is advantageous and preferred when the small container system isinstalled in the vicinity of the spraying elements, i.e. the sprayingelements, which are supplied with lacquer using the small containersystem, are preferentially connectable by short feed lines, i.e. alongthe shortest possible route, e.g. by short pipes or tubes to the smallcontainer system.

In the second embodiment of the invention, for example, each sprayingelement disposed inside spraying cabins C is connected by theconventional feed lines and ring lines to the lacquer storage containersfor standard colours. In addition, the spraying elements are connectableby short feed lines, i.e. along the shortest possible route, e.g. byshort pipes or tubes to the small container system for the speciallacquering processes. The feed lines to the ring line and/or the shortfeed lines are provided with valves, which in each case enable therequired supply of standard colour or special colour. The valves of thefeed line of a ring line and of the short feed lines may beautomatically coupled.

In the case of the apparatus according to the invention, each sprayingelement may be connected by a separate feed line to the lacquer supplyunit for the lacquer in a standard and/or special colour. Preferably,however, the feed lines of a plurality of spraying elements or of allspraying elements, especially when the latter are located close to oneanother, are combined into a single feed line and connected to therespective small container. For example, the spraying elements disposedat one side as well as the spraying elements disposed above the guidedevice may in each case be combined and connected by a single feed lineto the small container.

The spraying elements may also be connected by so-called colour changersto the feed lines for the standard and/or special colours. Such colourchangers automatically disconnect the one feed line at the end ofapplication of the corresponding colour, in-roduce rinsing liquid intothe system and then connect the new feed line for the next colour. Inthe second embodiment of the invention, for example, the sprayingelements may be connected by the colour changers to the feed lines forthe standard colours and to the short feed lines for the specialcolours. The colour changers automatically disconnect the conventionalring line systems at the end of one standard colour, introduce rinsingliquid into the system and then connect the new ring line for a furtherstandard colour. The short feed lines used in accordance with theinvention may also be integrated into said colour changing system sothat a switchover of the generally automatically operating colourchangers from standard colours to special colours and vice versa is madepossible.

The lacquer supply system comprising the small containers, the rinsingdevice and the lacquer conveying device, as well as optionallyapparatuses for connecting the lacquer conveying device to the smallcontainers and optionally automatic apparatuses for supplying andremoving the small containers, is preferably situated in the immediatevicinity of an optionally provided colour changer. It is thereby ensuredthat there are only short distances and hence only short clearancevolumes between small containers, colour changer and connecting lines tothe spraying elements. This leads to a low consumption of unused lacqueras well as to low quantities of the rinsing liquid required for cleaningthe lacquer conveying device, the stub lines and the spraying elements.

The lacquer supply device based on the small containers may, wherenecessary, also be disposed inside the lacquering cabins A and/or C, inwhich the spraying elements are situated. This is possible particularlybecause the small containers, as described above, are tightly sealed.Contamination of the contents, e.g. by spray mist, may thereby beavoided. It is also advantageous to screen off the lacquer supply unitbased on the small containers from contamination, especially by spraymist.

The lacquer supply unit for supplying the standard and/or speciallacquers comprises one or more exchangeable small containers. Thedimensions of the small containers may be adapted to requirements. Theirsize may, for example, be such that one or more containers are usablefor lacquering one body unit. It is however also possible to design thesmall containers in such a way that a plurality of vehicle bodies orparts thereof may be lacquered from a single small container. Generally,the filling volume of the small containers is preferably in the order ofmagnitude of 0.5 to 10 litres. The basic assumption is that thelacquering of one vehicle body generally requires a lacquer quantity inthe order of magnitude of 4 to 10 litres.

Tightly sealed small containers may be used so that contamination andfouling of the lacquer contents from the environment are avoided. It isadvantageous when the small containers have metal or plastic surfaces asthe latter may be cleaned at any time.

Conventional removal devices may be used to convey the lacquer out ofthe small containers. According to a preferred embodiment, a rising pipemay be introduced into the small containers. In addition, the lacquerconveying device is equipped, for example, with a pumping system or adevice for applying a pressure medium such as, for example, compressedair or an inert gas. According to a further preferred embodiment, thelacquer conveying device is designed in such a way that it may likewisebe introduced into the rinsing device, in which a rinsing solution issituated. By means of the pumping or pressure medium the rinsingsolution may, e.g. with an alternating air/rinsing agent flow, then beconveyed through the conveying device, the feed lines and the optionallyprovided colour changer to the spraying elements.

In a preferred manner, the lacquer conveying device may be connected ina sealing manner to the small container. For example, the lacquerconveying device may take the form of a bell, which may be placed in asealing manner over the small container. In a preferred manner, thelacquer conveying device may be introduced in a sealing manner into thesmall container. In the case of said embodiments, it is possible toconvey the lacquer by means of a pressure medium, such as compressedair, or by means of a pumping system to the spraying devices.

So that the lacquer conveying device in the form of a rising pipe usedin the preferred embodiment described above may be introduced in asealing manner into the small container, the latter may for example beprovided with a pierceable self-sealing closure. It is then possible,for example, for the line for the pressure medium also to be inserted ina self-sealing manner into said closure. The line for the pressuremedium may however alternatively be combined with the rising pipe, e.g.in the form of a double pipe. According to a further embodiment, risingpipe and pressure line may be integrated into a lid, which may be fittedtightly onto the small container.

The small containers may be made of various materials, for exampleplastic material or metal, e.g. sheet metal, aluminium, steel, and mayoptionally also be provided at the inside with a surface coating. Such asurface coating or the containers as such have to be inert to thelacquer contents. They may be handled like one-trip containers which aredisposed of, when empty. In a preferred manner, they are refillablecontainers which, when empty, may be cleaned and refilled in situ by theuser, e.g. the vehicle manufacturer. Cleaning and refilling of the smallcontainers is however preferably effected at the premises of the lacquermanufacturer or lacquer supplier. In the case of refillable containersand/or the use of aqueous lacquers, e.g. water-based lacquers, the smallcontainers are preferably made of special steel.

The closure of the small container may be formed, for example, from apierceable foil. The pierceable foil may be made of a material whichencloses the introduced conveying device in a self-sealing manner.

It is advantageous for the small containers to carry a featureidentifying their contents, e.g. a bar code which may be automaticallyread prior to opening of the small container. In a preferred manner, thebar code may also be used moreover to supply application data pertainingto the lacquer of the colour in question, e.g. for control of thespraying elements.

The design of the small containers as such is not subject to anyrestriction. It may be geared to the nature of the specific lacquersupply unit. Small container and lacquer conveying device are combined,as explained above, into a sealing lacquer supply system which may behandled automatically as a closed system. The small containers are, forexample, cartridges, tins, bottles or other containers which, forexample, have a capacity of between 0.5 and 10 litres. The smallcontainers may be in various shapes, e.g. they may be cylindrical,cuboidal or cube-shaped. At one end they have a closure, which may takethe form of a lid or a foil (e.g. made of metal or plastic material).The closure may alternatively take the form of a preformed segment ofthe container surface, e.g. a punched window, or a preformed outletspout.

The lacquer supply device preferably has an opening apparatus for thesmall containers. The small containers may therefore be connected forexample at the lid described above, e.g. by a piercing, cutting,pressing-in, drilling-through, screw-on action, to the lacquer conveyingdevice. In said case, the opening may be directed, for example, upwards;it may however alternatively be oriented in another direction, e.g.downwards.

The small container may also be of a compression-proof design, i.e. thelacquer may then be expressed from the small container by exertingexcess pressure with a pressure medium, e.g. air or an inert gas such asnitrogen. If the small container is not sufficiently compression-proof,it is then advantageous for the small container to be previouslyintroduced into a suitably shaped, larger, compression-proof outercontainer; this has the advantage that the outer container is also easyto seal with a preformed lid, into which the conveying device is or maybe integrated. In said case, it is possible to subject either only thesmall container or the entire outer container to a correspondingpressure in order to convey the lacquer out of the small container.However, another possibility is, for example, to use a pumping orsuction apparatus to convey the lacquer out of the small container. Insaid case, it is preferred when the shape of the small container is suchas to produce a minimum clearance volume with regard to the connectionto the lacquer conveying device. To said end, it is possible for e.g.the base or lid of the small container to have preferably an outwardlycurved conical or round shape.

The lacquer supply unit comprising small containers, conveying device,rinsing device and feed lines is preferentially used to supply lacquersin a standard and/or special colour to the spraying elements disposedinside lacquering cabins A and/or to supply lacquers in a special colourto the spraying elements disposed inside lacquering cabins C of alacquering line for the series lacquering of industrially manufacturedproducts, e.g. a motor vehicle lacquering line for series lacquering.The lacquer supply unit may have an opening device for the smallcontainers, which is used to enable the sealing connection of lacquerconveying device to small containers. It is advantageous to supplementthe lacquer supply unit with a feed device for one or more smallcontainers as well as a removal device for the emptied small containers.The feed device may be, for example, a transport belt or otherconventional feed device; the same applies to the removal device. Thelacquer supply unit then substantially comprises a device for feedingthe small containers to an opening device for the small containers, anda lacquer conveying device which connects in a self-sealing manner to ineach case one opened small container, a removal device for the emptysmall containers as well as an automatic rinsing apparatus for the partsof the lacquer supply unit which come in contact with lacquer, e.g. alsofor the opening device if it comes into contact with lacquer.

In a preferred manner, opening device and lacquer conveying device arecombined with one another, e.g. in the form of a piercing apparatus.Such a piercing apparatus, wherein the lacquer conveying device ispunched into the small container, is suitable when the closure lid orthe closure foil of a small container is pierceable.

When the small containers are, for example, cartridges containing thelacquer, said cartridges are connected to a lacquer conveying devicewhich is suitable for supplying the required quantity of lacquer to thespraying elements, e.g. through automatically controlled operation ofthe expressing apparatus of the cartridge, which has been opened, forexample, by cutting or piercing.

In the conveying device for the small containers, the small containersmay be secured, either directly or in a compression-proof outercontainer, by a holding apparatus. The holding apparatus may operate,for example, in a mechanical, pneumatic or magnetic manner. The lacquerconveying device may be inserted at the exposed side of the securedsmall container. In said case, it is possible to place a piercing,pressing or screw-type apparatus onto the small container. Saidapparatus is to effect sealing. The seal may be made, for example, of anelastic material such as rubber, Teflon or Viton. At the same time, theconveying device is introduced into the small container and positionedso as to be situated close to, or at, the lowest point of the container.The lacquer may then be conveyed out of the small container, e.g. byapplying pressure or by means of a suction pump. It is also possible forthe lacquer conveying device to be of an adjustable design which allowsit to be fitted in a sealing manner onto small containers of varyingsize. This promotes flexible use of the lacquer conveying device.

A device for rinsing the parts which come into contact with the lacqueris simultaneously integrated into the lacquer supply device. Said partsinclude the interior of the piercing apparatus, as well as the necessarypumps or pressure devices. By introducing a rinsing solution, thecorresponding stub lines to the spraying elements and the sprayingelements may also be cleaned. The same also applies to a colour changeroptionally inserted between stub lines and spraying elements. Therinsing device may for example be so designed that the lacquer conveyingdevice, after removal from the relevant small container, is introducedinto a container holding rinsing solution. By said means, the outerparts of the lacquer conveying device (particularly a rising pipe) whichcome into contact with lacquer are cleaned and, as a result of a pumpingoperation or application of a pressure medium, the rinsing solutionpasses also into the interior of the lacquer conveying system andreaches the further elements connected thereto. Generally, the rinsingoperation is effected with an alternating air/rinsing medium flow. Therinsing device is preferably so designed that lines are provided, whichconvey the rinsing liquid during the rinsing operation into a suitablecollecting container. It is also possible to install additional cleaningdevices which, after removal of the lacquer conveying device from therinsing device, remove any lacquer contamination still adhering to theoutside. The lacquer conveying device may then be fed to further smallcontainers which, for example, contain lacquers in further colours.

A further subject-matter of the invention is a method of lacqueringindustrially manufactured products, preferably motor vehicle bodies orindividual parts of motor vehicle bodies in standard and/or specialcolours in one of the lacquering lines for series lacquering which havebeen defined above as being in accordance with the invention. The smallcontainers are connected by the described conveying device as well asthe stub lines optionally via a colour changer directly to the relevantspraying elements, i.e. it is a closed system. After the required numberof products have been lacquered, the relevant lacquer supply unit isdisconnected and the conveying device with the stub lines is rinsed,rinsing being effected by the rinsing device of the lacquer supply unit.The disconnection may be effected by means of valves or by means of acolour changer. The spraying elements may also be cleaned by the rinsingdevice of the lacquer supply unit; cleaning of the spraying elements ishowever also possible by means of conventional rinsing devices oflacquering lines for series lacquering.

A further subject-matter of the invention is also a method of effectingspecial lacquering of individual motor vehicle bodies or individualparts of motor vehicle bodies within a conventional lacquering line formotor vehicle series lacquering. Said method is such that the individualbodies or parts to be lacquered are, without being transferred out ofthe conventional lacquering line, introduced by means of theconventional guide devices into a spraying cabin C having the sprayingelements used for the series lacquering. The ring and feed linesrequired for the series lacquering are disconnected by means of valvesor by means of an automatic colour changer and the spraying elements arecleaned by means of conventional rinsing devices. The lacquer supplyunit for supplying small quantities of lacquer is then provided with thequantity of small containers required for the individual lacquering,which small containers contain the requisite lacquer in a specialcolour. The small containers are connected by the described conveyingdevice as well as the stub lines optionally via a colour changerdirectly to the spraying elements. After the required number of bodiesor body parts have been lacquered, the lacquer supply unit integratedinto the lacquering line is disconnected and the conveying device withthe stub lines is rinsed, rinsing being effected by the additionalrinsing device of the lacquer supply unit. In said manner, a preciselymeasurable quantity of special lacquer for individual lacqueringoperations may be applied, with the result that an unnecessaryconsumption of lacquer as well as associated cleaning operations andenvironmental pollution may be avoided.

The invention makes it possible for lacquers in standard and/or specialcolours to be processed efficiently alongside one another in onelacquering line. The volume of lacquer waste arising from theapplication of special colours is markedly reduced compared to currentpractice.

The handling of liquid lacquer by the user in the form of filling andemptying operations as well as rinsing and cleaning operations isextensively or—in the case of exclusive lacquer supply via the smallcontainer system—totally avoided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows, schematically, a lacquering line having a lacquering cabinof type A.

FIG. 2 shows, schematically, a lacquering line having a lacquering cabinof type B.

FIG. 2a shows, schematically, a system of FIG. 2 having a colourchanger.

FIG. 2b shows, schematically, a lacquering line having a lacqueringcabin of type C.

FIG. 2c shows, schematically, a system of FIG. 2b having a colourchanger.

FIG. 3 shows, schematically, a lacquer supply unit for a lacqueringline.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The accompanying FIG. 1 diagrammatically illustrates an example of alacquering line having a lacquering cabin of type A. The products to belacquered are conveyed on a conventional guide device (1) to thespraying elements (2). The latter are situated in a spraying cabin A(not shown) so that they are sealed off from the environment. The Figureshows a lacquer supply unit comprising one or more small containers (inthe FIG. 2 small containers (6) and (6 a) are shown), which areconnectable by a conveying device (7) and stub line (8) as well asvalves to the spraying elements (2). To guarantee the connectability,the conveying unit (7) for example may take the form of a rising pipewith a pumping or pressure medium system, the rising pipe beinginsertable into the small containers (6), (6 a) or the rinsing device(9).

The accompanying FIG. 2 diagrammatically illustrates an example of alacquering line having a lacquering cabin of type B. The products to belacquered are conveyed on a conventional guide device (1) to thespraying elements (2). The latter are situated in a spraying cabin B(not shown) so that they are sealed off from the environment. The Figureshows two lacquer storage containers (3) and (3a) with the associatedring lines (4) and (4 a), which contain standard lacquers used forseries lacquering. Such an installation is naturally not limited to aspecific number of such lacquer storage containers and ring lines. Thenumber may be varied according to requirements. The standard lacquersrun through feed lines (5) and (5 a) via valve systems and conveyingdevices (not shown) to the spraying elements (2). A rinsing device (10),comprising a container for rinsing solution and a feed line (5 b) to thespraying elements, is used to clean the line systems as well as thespraying elements prior to a colour change, e.g. a change from container(3) to container (3 a).

The accompanying FIG. 2a illustrates the same system as described inFIG. 2; the reference characters each have the same significance as inFIG. 1. Unlike FIG. 1, the embodiment of the invention illustrated inFIG. 2 comprises a colour changer (11). Such a colour changerautomatically regulates the supply of lacquers from the individuallacquer storage containers (3) and (3 a) and the rinsing device (10) tothe spraying elements (2). One regulating unit is provided for eachlacquer system. The same applies to the rinsing device (10).

The accompanying FIG. 2b diagrammatically illustrates an example of alacquering line according to the invention having a lacquering cabin oftype C. The products to be lacquered are conveyed on a conventionalguide device (1) to the spraying elements (2). The latter are situatedin a spraying cabin C (not shown), so that they are sealed off from theenvironment. The Figure shows two lacquer storage containers (3) and (3a) with the associated ring lines (4) and (4 a), which contain thestandard lacquers used for series lacquering. Such an installation isnaturally not limited to a specific number of such lacquer storagecontainers and ring lines. The number may be varied according torequirements. The standard lacquers run through feed lines (5) and (5 a)via valve systems and conveying devices (not shown) to the sprayingelements (2). A rinsing device (10), comprising a container for rinsingsolution and a feed line (5 b) to the spraying elements, is used toclean the line systems as well as the spraying elements prior to acolour change, e.g. a change from container (3) to container (3 a).Integrated into the system is a lacquer supply unit, comprising one ormore small containers (in the Figure two small containers (6) and (6 a)are shown), which are connectable by a conveying device (7) and stubline (8) as well as valves to the spraying elements (2). To guaranteeconnectability, the conveying unit (7) for example may take the form ofa rising pipe with a pumping or pressure medium system, the rising pipebeing insertable into the small containers (6) (6 a) or the rinsingdevice (9).

The accompanying FIG. 2c illustrates the same system as described inFIG. 2b; the reference characters each have the same significance as inFIG. 2b. Unlike FIG. 2b, the embodiment of the invention illustrated inFIG. 2c comprises a colour changer (11). Such a colour changerautomatically regulates the supply of lacquers from the individuallacquer storage containers (3) and (3 a) and the rinsing device (10) tothe spraying elements (2). one regulating unit is provided for eachlacquer system. The same applies to the rinsing device (10). Aregulating unit is also provided for the additional lacquer supply unitused in accordance with the invention which comprises small containers(6, 6 a), rinsing device (9) as well as lacquer conveying device (7) andstub line (8).

The lacquering line according to the invention may be provided with oneor more lacquer supply units based on small containers if frequentlyalternating different individual lacquering operations are carried out.In such a case, the colour changer (which is indicated in FIG. 2c by thereference character (11)) comprises a separate regulating unit for eachlacquer supply unit.

FIG. 3 shows an example of an embodiment of the lacquer supply unitprovided according to the invention within a lacquering line For theseries lacquering of motor vehicle bodies or parts thereof.

Situated on a conveying device (16), formed in the present example by aconveyor belt, are holding devices (12) for small containers (6). Thesmall containers are provided with a lid (13). They are conveyed by thetransport device (16) past a bar-code laser (14), which may read a codeoptionally provided on the lid (13). The small containers (6) are fed toan opening device (15), where a conveying device is introduced in aself-sealing manner. This is effected in the present specific example bya piercing apparatus. The conveying device comprises a rising pipe (7 a)and, in the case of the present example, a device (7 b) for supplying apressure medium, e.g. compressed air. In a similar manner, however, apumping device might be provided for extracting the contents from thesmall containers (6). The rising pipe (7 a) opens into the stub line(8). The latter leads (no longer shown in FIG. 3) optionally via acolour changer to the spraying elements. Integrated into the lacquersupply unit is a rinsing device (9) which, in the present example, is sodesigned that the rising pipe, after emerging from the small container(6), plunges into a rinsing vessel containing rinsing solution. Therinsing solution may be conveyed by a pumping or pressure medium deviceinto the rising pipe (7 a) and through the stub line (8) optionally viathe colour changer to the spraying elements. Upon completion oflacquering, the small containers (6) are removed by the conveying device(16) and may then be disposed of or collected for subsequent cleaningand refilling.

The lacquers in different colours, e.g. a standard and/or specialcolour, which are usable in the apparatus according to the invention andfor the method according to the invention are packed ready forapplication into small containers. Packing of the ready-to-applylacquers into the small containers may be effected at the premises ofthe lacquer processor, e.g. the automobile manufacturer, but ispreferably effected at the premises of the lacquer manufacturer orlacquer supplier. Shortly before application, e.g. prior to breakingopen the respective small container, its contents are advantageouslythoroughly mixed, e.g. by shaking the small container in a conventionalshaking device. Particularly the lacquers in a special colour arepreferably not produced from scratch, this being, in the case of asingle product or only a low piece number of products to be lacquered ina special colour, disadvantageous from both an economic and practicalstandpoint, but are preferably produced by the method known, forexample, from the field of bodywork repair lacquers using mixed lacquersor semi-finished products, so-called modules. The packed lacquercontainers may be used, as described above, directly as small containersprovided they are connectable particularly in a sealable manner to alacquer conveying device. They may however alternatively be insertedinto, in particular, compression-proof outer containers serving as smallcontainers, which as such may be sealably connected to the lacquerconveying device.

The invention may be used both in the field of mechanical lacquering andin particular for the lacquering of products manufactured on anindustrial scale using lacquers of different colours, e.g. in specialand/or standard colours. Said lacquers in different colours are inparticular colour- or effect-lending base or coating lacquers. Theinvention may however be used also with other lacquers in differentcolours, e.g. clear lacquers of differing transparent tints or fillerlacquers.

What is claimed is:
 1. A lacquering line for lacquering industriallymanufactured products in at least one of standard colours and specialcolours, comprising: one or more guide devices (1) for the industriallymanufactured products, having one or more lacquering cabins and havingspraying elements (2) disposed along the guide devices (1) inside thelacquering cabins, wherein at least one lacquering cabin comprises oneor more lacquering units, said lacquering units comprising one or moreexchangeable small containers (6, 6 a) in which a lacquer quantityrequired for lacquering a predetermined number of individual products ispacked ready for application, and a rinsing device (9), wherein thesmall containers (6, 6 a) and the rinsing device (9) are eachconnectable by a lacquer conveying device (7) and one or more stub lines(8) directly or via a colour changer (11) to the spraying elements (2),wherein the small containers (6, 6 a) are closed and connectable in asealing manner to the lacquer conveying device (7), wherein the lacquerconveying device (7) comprises a rising pipe (7 a) insertable into thesmall containers (6, 6 a) and a device for pumping or applying apressure medium, wherein the rising pipe (7 a) comprises a piercingapparatus.
 2. An apparatus according to claim 1, wherein the lacqueringunits comprising small containers (6, 6 a) are provided in separatelacquering cabins integrated into the lacquering line.
 3. An apparatusaccording to claim 1, wherein the lacquering units comprising smallcontainers (6, 6 a) are integrated into lacquering cabins provided withone or more ring lines.
 4. A lacquering line according to claim 1,wherein at least one first lacquering cabin comprises one or more unitsfor lacquering industrially manufactured products, wherein one said unitcomprises one or more of the exchangeable small containers (6, 6 a), inwhich the lacquer quantity required for lacquering a predeterminednumber of individual products is packed ready for application, and arinsing device (9), and wherein the one or more small containers and therinsing device are each connectable by the lacquer conveying device (7)and one or more stub lines (8) directly or via a colour changer to thespraying elements, and optionally, for lacquering in standard coloursthe lacquering line further comprises one or more second lacqueringcabins comprising spraying elements, which are disposed along the guidedevices inside said lacquering cabins and are connected by feed lines(5, 5 a) via one or more ring lines (4, 4 a) to one or more lacquerstorage containers (3, 3 a) and connected by feed line 5 b to a rinsingdevice (10).
 5. A lacquering line according to claim 1, comprising oneor more third spraying cabins, in which are disposed spraying elements(2) connected by feed lines (5, 5 a) via one or more ring lines (4, 4 a)to one or more lacquer storage containers (3, 3 a) and a rinsing device(10), and the third spraying cabins comprise in an integrated manner oneor more lacquering units, wherein one of said lacquering units comprisesone or more of the exchangeable small containers (6, 6 a), the totalfilling volume of which corresponds to the lacquer quantity required forlacquering a predetermined number of individual products, as well as anadditional rinsing device (9), wherein the small containers (6, 6 a) andthe additional rinsing device (9) are connectable in each case by thelacquer conveying device (7) and one or more stub lines (8) directly orvia a colour changer (11) to the spraying elements.
 6. A lacquering lineaccording to claim 5, comprising as spraying cabins, exclusively one ormore of the third spraying cabins.
 7. A lacquering line according toclaim 4 comprising one or more of the first lacquering cabins forlacquering in special colours and one or more of the second lacqueringcabins for lacquering in standard colours.
 8. A lacquering lineaccording to claim 1, for lacquering in special colours and standardcolours, comprising one or more of the first lacquering cabins.
 9. Amethod for using a lacquering line according to claim 1, comprising:lacquering motor vehicle bodies or parts thereof.
 10. A lacquering lineaccording to claim 1, wherein the lacquering line comprises only onefirst lacquering cabin.
 11. A lacquering line according to claim 1,wherein the one or more small containers (6, 6 a) are located in thevicinity of the spraying elements (2).
 12. A lacquering line accordingto claim 4 wherein at least one of the feed lines (5, 5 a) of the ringlines (4, 4 a), the feed line (5 b) of the rinsing device (10), and thestub lines (8) are connected by a colour changer to the sprayingelements (2).
 13. A lacquering line according to claim 12, wherein thesmall containers (6, 6 a) are located in the vicinity of the colourchanger.
 14. A lacquering line according to claim 1, wherein theexchangeable containers (6, 6 a) each have a filling volume of 0 0.5 to10 litres.
 15. A lacquering line according to claim 1, wherein the smallcontainers (6, 6 a), the lacquer conveying device (7) and the rinsingdevice (9) are located in the vicinity of the spraying elements (2). 16.A lacquering line according to claim 1, wherein the small containers (6,6 a) and the lacquer conveying device (7) connectable thereto arescreened off for preventing contamination.
 17. A lacquering lineaccording to claim 1, comprising an automatic conveying device forsupplying the small containers (6, 6 a) to the lacquer conveying device(7).
 18. A lacquering line according to claim 1, comprising an automaticdevice for connecting the small containers (6, 6 a) to the lacquerconveying device (7).
 19. A method for lacquering industriallymanufactured products, comprising: lacquering in a lacquering lineaccording to claim
 1. 20. A method according to claim 19, comprising,for individual lacquering, using small containers holding lacquer, thetotal filling volume of which corresponds to a lacquer quantity requiredfor individual lacquering.
 21. A method according to claim 19,comprising: upon completion of lacquering or individual lacquering,cleaning the lacquer conveying device, the feed lines from the smallcontainers to the spraying elements and the spraying elements, with arinsing solution.